Confused about the difference? Here, GRTW Head Honcho of online running programmes, Tara Shannahan explains and how it can make you a faster runner
An Interval run is when you run fast for an interval of time, then allow the body to partially recover and then repeat.
Why do we run intervals?
The purpose of these runs are to train our VO2 max, which means the maximum amount of oxygen your body can process to fuel your run. Your VO2 max is determined by two things – the ability of your heart to pump oxygenated blood around the body and the ability of your muscles to extract this oxygen from your blood and use it to fuel your run.
Think of these runs as heart training, by running fast you’re forcing your heart to work really hard which is what will make it stronger and you faster.
So how fast is fast?
Well this depends on the length of the interval. For example, a three minute interval will be run slightly faster than a five minute interval. The goal is to run at a challenging but even pace.
Tempo runs, sometimes called Threshold or Lactate Threshold runs are similar to interval runs but the intervals are longer and slower.
Why do we run tempo runs?
They are designed to train your body’s ability to deal with lactic acid which is caused by a chemical response in the body, which releases the energy to fuel the muscles. The chemical byproduct of which is lactic.
When we run more slowly, the lactic acid we produce is easily dealt with. But when we move really fast the lactic acid builds up which is what causes heavy legs and slowing down. These tempo runs should be done at the pace when your body is just about coping with clearing the lactic acid. If you go too fast you will accumulate acid rather than clear it and if you go too slow you won’t be producing enough acid to train your body to clear it!